Lift leg structure



Dec. 13, 1966 1.BAREc| ETAL 3,290,700

LIFT LEG STRUCTURE 5 Sheets-Sheet 1 Filed Jan. 10, 1966 5 5 00 Q0 4\ 3 3I-.. 2 I 1 w "3 2 w m m FIG. 3-

INVENTOR Chester J. Burecki Robert L. Knapp @awuow, Jlfmu, 70%122, 6

WITNESS ,alwfivllbumdwu ATTORNEY FIG. 5

Dec. 13, 1966 c. J. BARECKl ET AL 3,290,700

LIFT LEG STRUCTURE 5 Sheets-Sheet 2 Filed Jan. 10, 1966 R m. M m m O 7 w1 n o e a A ?u u m um N am 4 F 2 O J J m 67 33 F Q Va n m I s CRQE 3 Y 4B VI 2 -l\ J n7 C" T 5 1/: 31 2 Q: \.I Q" m m m n PB J. 4 E Hun 97 l- [A2L -1 W Dec. 13, 1956 c BARECKl ET AL 3,290,790 7 LIFT LEG STRUCTUREFiled Jan. 10, 1966 5 Sheets-Sheet 3 IA F56. i6

INVENTOR Chester J. Barecki Weber? L. Knapp WITNESS BY w mu J/lfimv, 111112111,

United States Patent Filed Jan. 10, 1966, Ser. No. 519,488 6 Claims.(Cl. -63) This invention relates to a lift leg structure, and isparticularly useful in connection with a leg for lifting and lowering ahospital bed section. For the purpose of illustration, the inventionwill be described herein as a leg structure for a hospital bed.

An object of the present invention is to provide a lift leg structurewhich improves the lifting and lowering operation of a member such as,for example, a hospital bed section. A further object is to provide insuch a lift leg structure a sheave or pulley wheel structure in whichthe sheave serves also as a guide while keeping the lifting or tensionelement close to the center of the inner or fixed leg. A still furtherobject is to provide in such a structure a leg cylinder formed as anextrusion casting and providing locking or holding elements for theanchor cap and caster stem. A still further object is to provide a'unique inner leg structure and a cooperating outer leg or sleeve withsheave slots which eliminate the need for rightor left-hand legbrackets. Other specific objects and advantages will appear as thespecification proceeds.

The invention is shown in illustrative embodiments, by the accompanyingdrawings, in Which- FIG. 1 is a perspective view of a hospital bed ofthe electrically-operated type equipped with push button controls; FIG.2, a perspective view of a similar bed which is howevermanually-operated and is equipped with hand-operated cranks; FIG. 3, atop plan view of a typical bed frame adapted to be used with either ofthe beds shown in FIGS. 1 and 2 and in which tension elements (partiallybroken away) are shown for operating the lift leg structure; FIG. 4, aside view in elevation of the structure shown in FIG. 2 and with the bedsection shown in elevated position; FIG. 5, a view similar to FIG. 4 butshowing the bed section in lowered position; FIG. 6, a broken top planview of a portion of the bed section equipped with a leg assemblyembodying our invention; FIG. 7, a partial vertical section of thestructure shown in FIG. 6, the section being taken as indicated at line7-7 of FIGS. 6 and 9; FIG. 8, a broken side view in elevation, the viewbeing taken as indicated at line 8-8 of FIG. 6; FIG. 9, a transversesectional view, the section being taken as indicated at line 9--9 ofFIG. 7; FIG. 10, a side view in elevation of the lift leg structure on areduced scale but showing the bed section in lowered position and alsoshowing the bed section in phantom lines in elevated position; FIG. 11,a broken top plan view of the bed section equipped with a modified formof lift leg structure in which the outer leg or sleeve is provided withtwo slots, thus eliminating the need for rightor left-hand leg brackets,the leg being on the right side of the bed; FIG. 12, a view similar toFIG. 11 but showing the lift leg structure on the left side of the bed;FIG. 13, a sectional view, the section being taken as indicated at line13-13 of FIG. 11; FIG. 14, a side view in elevation, the view beingtaken as indicated at line 14-14 of FIG. 11; FIG. 15, a transversesectional view, the section being taken as indicated at line -15 of FIG.14 and FIG. 16; and FIG. 16, a detail sectional view, the section beingtaken as indicated at line 1616 of FIG. 15.

In the illustration given in FIGS. 110 inclusive, A indicates amanually-operated hospital bed and A an 3,299,700 Patented Dec. 13, 1966electrically-operated hospital bed. In the operation of either form ofbed for lifting and lowering the bed section, it is common to employ atension element 10 for lifting or lowering one end of the bed andtension elements 11 for lifting the other end of the bed. Tensionelement 10 engages a draw bar 12 to which are secured two cables ortension elements 13 and 14. These extend around inclined sheaves 15 and16 and operate the lift bed structure at the corners of one end of thebed. Similarly, the lift elements 11 pass around inclined pulley wheels17 and 18 and operate the lift leg structures at the other end of thebed. Since such structures are well known, a detailed description hereinis believed unnecessary. In practice, an actuating bar manipulates boththe tension element 10 and the tension elements 11 and such a bar may bemanually operated or operated by an electric motor.

As shown best in FIGS. 4 and 5, the bed structure 19 is supported uponinner legs 20 and is arranged to move upwardly and downwardly on theinner legs 20, the bed 19 being shown in elevated position in FIG. 4 andin lowered position in FIG. 5.

The lift leg structure is shown in detail in FIGS. 610 inclusive. At thecorner of the bed, as shown best in FIG. 6, the bed frame is providedwith a bed side angle member 21 and a cross angle member 22. Suspendedfrom the two angle members is a bracket member 23 which extendsdownwardly and is provided at its lower end with a sleeve or outer leg24. Spacer members 25 and 26 are provided for supporting the bracket 23,as shown best in FIGS. 7 and 8.

The sleeve member or outer leg member 24-, as shown best in FIG. 9, isprovided with a slotway 27 for receiving a sheave or pulley wheel 28,and a sheave pin 29 extends across the slotway and is-held by roll pins30. A tension element, which is desginated as element 11 but which may'be any of the tension elements shown in FIG. 3, as, for example,elements 13 and 14, extends around the sheave 28 and is secured to theupper end of the inner leg ,20.

The inner leg 20 may be formed in any suitable manner and of anysuitable material. We prefer to form it of aluminum or aluminum alloyand to extrude the same in the shape and form illustrated in FIGS. 7, 8and 9. The portion of the cylinder near the sheave 28 is provided with adeep groove 31 to receive the inner portion of the sheave and thus bringthe tension element 11 close to the center or vertical axis of the innerleg 20. Also, the cylinder is provided with radial webs 32 which extendinwardly and merge with a ring member 33. The ring 33 is provided at itstop. with threads for receiving a screw 34 which holds the anchor cap 35in position on the top of the cylinder 20. At the bottom of the cylinderor inner leg 20, there is received the crown 36 of the anti-frictionrace mounted on the bracket 37 of the caster 38, and the ring 33receives the stem 39 of the caster. Thus the ring 33 serves at its upperend for securing the anchor cap in place, while at its lower end itreceives and supports the stem or pin of the caster member, as shownbest in FIG. 9.

Any suitable bearings may be provided between the sleeve or upper legmember 24 and the inner leg or cylinder 20. As shown best in FIG. 6, weprovide bearings 40 and 41 at the top portion of the member 24 and bearings 42 and 43 at the lower portion of the member 24.

In the lower portion of the inner leg 20 are stop screws 44 havinghexagonal heads and limiting the downward movement of the member 24. Ifdesired, a single stop 44 will suffice for limiting such movement.

The tension element 11, as shown best in FIG. 8, is provided at itsupper end with a threaded portion 45 which extends through and issecured by a nut 46, as

shown best in FIG. 8.

Operation In the operation of the structure shown in FIGS. 1-10inclusive, when the outer leg or sleeve 24 is in lowered position, asillustrated in FIG. 10, and when the ten sion element 11 is drawninwardly, this causes the sheave 28 together with the outer sleeve orleg 24 to move upwardly along the fixed leg 20 to the raised positionshown in dotted lines in FIG. 10. Similarly, when the cable or tensionmember 11 is slackened, the weight of the bed section causes the outerleg 24 to drop to the lower position shown in solid lines in FIG. 10. Inthese operations, the pulley or sheave 28 holds the tension elementinwardly close to the vertical axis of the inner leg 20 while at thesame time the sheave itself serves as a key or guide to cause verticalmovement of the sleeve and bed section along inner leg 20. In theseoperations, the central ring 33 of the inner leg casting serves to holdthe screw 34 in position and the anchor .33 in its lower end receivesand holds the stem 39 of the caster.

In the modification illustrated in FIGS. 1116 inclusive, the lift legstructure is substantially the same as that described in FIGS. 110inclusive except that the outer leg or sleeve 24a is provided with twoslots 27a for alternately receiving the sheave 28a, thus eliminating theneed for rightor left-hand leg brackets. FIG. 11 shows the bracketstructure on one side of the bed, while FIG. 12 shows the structure onthe other side of the bed.

To change the leg assembly from right-handed to left-handed, it ismerely necessary to remove one of the roll pins 30a, withdraw the sheavepin 29a, remove the sheave 28a, and rotate the inner leg 20a until thegroove 31a is aligned with the right-hand slot of the outer leg. Thenthe sheave, sheave pin and roll pin are inserted to secure the sheave inthe new slot.

In the structure shown in FIGS 11-16 inclusive, we provide the inner leg20a with a slight tip or projection 47 which keeps the plastic bearing48 from turning. The one-piece bearing 48 is shown in detail in FIG. 16.

The operation of the structure shown in FIGS. 11-16 is in other respectsthe same as that described for the structure shown in FIG. 1-10, thetension element 11a extending about the sheave 28a and being heldagainst the anchor cap a by the nut 46a, the outer leg and the bedsection being raised as the tension element 11a is drawn and beinglowered as the tension element is slackened.

While in the foregoing specification we have set out structure inconsiderable detail for the purpose of illustrating embodiments of theinvention, it will be under- 4. stood that such details may be variedwidely by those skilled in the art without departing from the spirit ofour invention.

We claim:

1. In a lift device, telescoping inner and outer cylindrical legs, saidinner leg being adapted to rest upon the floor and having a verticalportion thereof turned inwardly to provide a grooved keyway bearing,said outer leg being fixed to a member to be lifted and provided with aslot and with radially-extending flanges providing a sheave bearing, asheave between said flanges, a transverse sheave pin extending throughsaid flanges and sheave, said sheave extending into said keyway forengagement therewith as a key, and a tension element extending aboutsaid sheave and within said keyway and having its end fixed to an upperportion of said inner leg.

2. The structure of claim 1 in which said sheave has its peripheralportion recessed to receive said tension element and haslaterally-extending peripheral bearing surfaces for engagement with saidkeyway bearing.

3. The structure of claim 2 in which said peripheral bearing surfaceshave portions projecting outwardly from the cylindrical leg and adjacentthe peripheral bearing surfaces of said sheave.

4. The structure of claim 1 in which said outer leg is provided with twopairs of radially-extending sheavesupporting flanges, said pairs offlanges extending sub-- stantially at right angles to each other.

5. The structure of claim I in which said inner leg is provided with acentral integral ring having radial webs connecting it to thecylindrical wall of the inner leg and having one web connecting saidring to said keyway bearing.

6. In a hospital bed, a bed section equipped at four sides withtelescoping inner and outer cylindrical legs, said inner legs havingtheir lower ends adapted to rest upon the floor and each being providedwith an in Wardly-turned vertical portion providing a grooved keywaybearing and each of said outer legs being provided with a transverseslot equipped with a sheave pin, a sheave within each of the slots andcarried by said sheave pin with the inner end of the sheave extendinginto said keyway for engagement therewith as a key, and a tensionelement extending about said sheave and secured to the top portion ofsaid inner leg.

References Cited by the Examiner UNITED STATES PATENTS 2,872,688 2/1959Reichert et al. 553 3,132,351 5/1964 Huntress et a1. 5-63 3,217,33911/1965 Black et a1. 5-63 FRANK B. SHERRY, Primary Examiner.

CASMIR A. NUNBERG, Assistant Examiner.

1. IN A LIFT DEVICE, TELESCOPING INNER AND OUTER CYLINDRICAL LEGS, SAIDINNER LEG BEING ADAPTED TO REST UPON THE FLOOR AND HAVING A VERTICALPORTION THEREOF TURNED INWARDLY TO PROVIDE A GROOVED KEYWAY BEARING,SAID OUTER LEG BEING FIXED TO A MEMBER TO BE LIFTED AND PROVIDED WITH ASLOT AND WITH RADIALLY-EXTENDING FLANGES PROVIDING A SHEAVE BEARING, ASHEAVE BETWEEN SAID FLANGES, A TRANSVERSE SHEAVE PIN EXTENDING THROUGHSAID FLANGES AND SHEAVE, SAID SHEAVE EXTENDING INTO SAID KEYWAY FORENGAGEMENT THEREWITH AS A KEY, AND A TENSION ELEMENT EXTENDING ABOUTSAID SHEAVE AND WITHIN SAID KEYWAY AND HAVING ITS END FIXED TO AN UPPERPORTION OF SAID INNER LEG.